Little marketing question.

Guys, I'm making a classic side scroller with more than 20 levels.
It's almost release time, and the question is:

Option 1: Release a free demo APK with only a few levels and a separated paid APK with the full game, turning the download size smaller.

Option 2: Release both at the same APK and use IAP to unlock the full game, turning the file size bigger, but "growing" the download rate since the beginning (even if the player don't buy the complete game latter).

Definitely option 2. If a player is enjoying your game you want to make that purchase as easy as possible for them. I'd also consider using ads in the free version which are also removed when an iap is made.